Related papers: Internal structure of $T_{cc}$ and $X(3872)$ by us…
The quantum numbers J^PC = 1++ of the X(3872) and the proximity of its mass to the D*0 anti-D0 threshold imply that it is either a loosely-bound hadronic molecule whose constituents are a superposition of D*0 anti-D0 and D0 anti-D*0 or it…
A coupled channel analysis of the $D^{\ast+}D^0$ and $D^{\ast0}D^+$ system is performed to study the doubly charmed $T_{cc}^+$ state recently discovered by the LHCb collaboration. We use a simple model for the scattering amplitude that…
We study the structure of constituent quarks by dressing bare quarks with the Goldstone bosons and its implications for quark distribution functions of hadrons $f_1(x)$, $g_1(x)$ and $h_1(x)$. In particular we discuss effects of the…
The X(3872) resonance is considered as a hadronic molecule, a loosely-bound state of charmed D0 and D*0 mesons, since its mass is very close to the D*0 barD0 threshold. Assuming structure and quantum numbers of X(3872) as (D0 barD*0 - D*0…
We investigate the static electromagnetic properties of three charm--strange molecular tetraquark candidates with quantum numbers $J^{P}=1^{+}$, namely the $D\bar{K}^{\ast}$, $D^{\ast}\bar{K}$, and $D^{\ast}\bar{K}^{\ast}$ systems. The…
Detailed investigations of the structure of hadrons are essential for understanding how matter is constructed from the quarks and gluons of Quantum chromodynamics (QCD), and amongst the questions posed to modern hadron physics, three stand…
We propose a new interpretation of the neutral and charged X, Z exotic hadron resonances. Hybridized-tetraquarks are neither purely compact tetraquark states nor bound or loosely bound molecules. The latter would require a negative or zero…
If the X(3872) resonance is a shallow boundstate of a the charm mesons $D^{0} \bar D^{*0}$ and $D^{*0} \bar D^{0}$, it can be described by an effective theory of nonrelativistic D mesons coupled to nonrelativistic pions (X-EFT). In this…
The models for the internal structure of the newly found four-quark charmonium-like resonance $Z_c(3900)$ are discussed: the molecular model as well as the hadro-charmonium and tetraquark schemes. It is argued that it would be possible to…
The discovery of the $D^\ast_{s0}(2317)$ and $D_{s1}(2460)$ resonances in the charmed-strange meson spectra revealed that formerly successful constituent quark models lose predictability in the vicinity of two-meson thresholds. The…
Recently, the LHCb Collaboration reported a near-threshold enhancement, $X(3960)$, in the $D_s^+D_s^-$ invariant mass distribution. We show that the data can be well described by either a bound or a virtual state below the $D_s^+D_s^-$…
An effective model with constituent quarks as fundamental degrees of freedom is used to predict the relative strangeness production pattern in both high energy elementary and heavy ion collisions. The basic picture is that of the…
Tremendous progress has been made experimentally in the hadron spectrum containing heavy quarks in the last two decades. It is surprising that many resonant structures are around thresholds of a pair of heavy hadrons. There should be a…
We study the $DN$ and $D^\ast N$ interactions to probe the inner structure of $\Sigma_c(2800)$ and $\Lambda_c(2940)$ with the chiral effective field theory to the next-to-leading order. We consider the contact term, one-pion-exchange and…
Within conventional constituent-quark models hadrons come out as stable bound states of the valence (anti)quarks. Thereby the resonance character of hadronic excitations is completely ignored. A more realistic description of hadron spectra…
Very recently a new hadronic structure around $3.98$ GeV was observed in BESIII experiment. From its decay modes, it is reasonable for people to assign it to the category of exotic state, say $Z^+_{cs}$, the stranged-parter of…
We investigate the structure of constituent quarks and study implications for quark distribution functions of hadrons. Constituent quarks are constructed by dressing bare quarks with Goldstone bosons using the chiral quark model. We…
In this work, we predict a new physical phenomenon, induced fission-like process and chain reaction of hadronic molecular states. As a molecular state, if induced by a $D$ meson, the $X(3872)$ can split into $D\bar{D}$ final state which is…
We investigate the role of the electromagnetic interaction in the formation and decay of the $X(3872)$. The binding properties of the $X(3872)$ are studied by assuming the molecular nature and considering the $S$-$D$ wave mixing, isospin…
Bound states of double-heavy tetraquarks are studied in a constituent quark model. Two bound states are found for isospin and spin-parity I(J^P ) = 0(1^+) in the bb\bar{u}\bar{d} channel. One is deeply bound and compact made of colored…